Regulator for mixed-pressure turbines.



W. PAPE. REGULATOR FOR MIXED PRESSURE TURBINES.

2 SHEETSSHEET 1.

Inventor; elm apa,

Mtfig,

Wilh y gm.

W. PAPE.

REGULATOR FOP. MIXED PRESSURE TURBINES.

'APPLIOATION FILED JAN. 21,1913. 1 U9Q,948u Patented Apr. 14, 1914.

2 SHEETS-SHEET 2.

J ll

un l l l'll COMPANY, A CORPORATION OF NEW YORK.-

REGULATOR FQR llIIXED-PRESSURE TURBINES.

Specification of Letters Patent.

Application filed January 21, 1913.

Patented Apr, Mt, 1914i. Serial No. 743,334.

To all whom, it may concern Be it known that I, W lLI-IELM PAPE, asubject of the King of Prussia, residing at Charlottenburg, Germany,have invented certain new and useful Improvements in Regulators forMixed-Pressure Turbines, of which the following is a specification.

This invention relates to elastic-fluid turbines, and more especially tothose in which the motive fluid employed is primarily low pressuresteamsupplied from a high pressure engine, or from industrial systems ofheating, cooking and the like. In such installations, however, it iscustomary to provide some means for supplementing the low pressure steamwith steam at boiler pressure 1 in case the supply of low pressure fluidbecomes inadequate to carry the load.

My invention has to do with such an installation commonly termed a mixedpres sure turbine, and its object is to afford a simple system of valvesand levers by means of which the steam from the two sources will beautomatically supplied to the turbine in such quantities as may benecessary to meet the varying conditions of service. The regu latingmembers are arranged to be acted on not only by a speed governor butalso by a n'essureresponsive device.

A perfectly working mixed pressure regulator must fulfil the followingconditions:'

. First, upon variations of load the speed governor must first move onlythe low pressure valve, and when this has reached its final positionmust influence'also the high pressure valve. Second, at any desiredposition of the low pressure valve, the high pressure valve must beadapted to operate directly in case of further action by thespeedgovernor. It the low pressure valve is held in any de siredposition, either by mechanical means or by the influence of thepressure-responsive device. then the process of regulation on the highpressure side must be capable of being associated with the regulatingprocess for the low pressure side. Third, when any influence is exertedby the pressure-responsive device, the two valves must be moved inopposite directions in such manner that the load on the machine as awhole and there with the number of revolutions will remain t-tmstant.Fourth, means must be provided for hand regulation of the pilot valvesin the v alve-actuating motors, while the machine is rimning, in orderto permit the two sides to operate properly. Fifth, thepressure-responsive device must be able to influence the low pressurevalve without acting upon the high pressure valve. Sixth, if the lowpressure valve is entirely open and there is sufficient low pressuresteam, then if an oven, load occurs, the speed governor must be able toopen the high pressure valve without actmg on the pressure-responsivedevice, since otherwise the ratio of synchronism of the governor wouldbe strongly afi'ected. All these conditions are provided for in theconstruction torming the subject-matter of the present application. Bythe ,addition of a single connecting rod between two valve systems, thehigh pressure and the low pressure,

a very simple and compact arrangement of a mixed pressure regulator hasbeen secured. The invention is shown diagrammatically in theaccompanying drawing wherein- Figure 1 shows one form which in invention may take, and Fig. 2 shows th second form thereof.

The low pressure valve 1 and the high pressure valve 2 are provided withidentical actuatiitg motors, comprising a piston 3, 3 working in acylinder 4, 1 and attached to the stem 5, 5 of its respective valve. Thepilot valve 6, 6 which controls the admission of hydraulic pressure tosaid cylinder is a double piston valve, as shofvvn, and Works in/ asleeve 7 7 COIltfiJIllINLthQPOIt'S 8,8, 9,9,

said sleeve being slidahle len'gthwise in the valve chest 1O, 10 A lever11, 11' is pivoted to the upper end of the valve stem 5, 5 and isfulcrumed on a block 12, 12 which can be moved longitudinally of saidlever, so as to vary the effective length of the same." Be tween saidblock and the stem is pivoted a link 13, 13 which is connected to thesleeve 7, 7. The pilot valve 6 of the low pressure valve is connected toa lever 14 which is pivoted at its other end to the movable collar 15 ofa speed governor 16. At some intermediate point a rod 17 is pivoted tosaid lever and conveys thereto the movements of a pressure-responsivedevice, consisting of a movable abutment 18 biased in one direction by aspring 19 and exposed on its opposite side to the pressure of the lowpressure steam, conveyed through a pipe 20. The

pilot valve 6 of the high pressure valve motor is connected to a lever21 pivoted at its nected one end of a longlever 22, fulcru-Ined at 23and .connected at its other end to the steinj of the low pressure valve.The lever 14 is fulcrumed on the upper end of the stem.17, while thelever 21 is .fulcrumed on the end of the long lever 22.

It ,will be observed that both pilot valves are connected to the speedgovernor, so that both tend to move simultaneously in the samedirection. The lever 22, however, prevents-this, 'and compels them tooperate in high pressure valve series. For example, the balls of thespeed governor drop and the collar 15 pushes down the adjacent ends ofthe levers 14: and 21 and these in turn push up the pilot valves'6, 6.Hydraulic pressure flowsto the-under side of the piston 3' at tached tothe low pressure valve and opens said valve farther to admit more "steamto the engine. But this movement of the stem 5 of said valve operates.the lever 22, which acts to pull down the pilot valve 6" of the to itsmid-position, so that the opening of the high pressure valve isprevented. This operation is'repeated until the piston 3 and its stem 5have reached their highest positions, that is to say, when the lowpressure valve is wide open. In this situation, any further dropping ofthe balls of the speed governor will actuate the levers 14, 21 asbefore, but the lever 22 will not be actuated because the stem 5 willremain at rest; The shifting of the pilot valve 6' will thenbe effectiveto cause its motor to operate and admit steam through the high pressurevalve.

In the operation of,each valve, the up- 'ward movement of the stem 5, 5"lifts the lever 11, 11. and therebyslides the sleeve 7,

7 upward until its ports are again closed bvthe pilot valve and .themovement of the piston 3, 3 is arrested. In other words, the levers 11,11 and the sleeves constitute follow-up devices for preventing anover-travel of the valve. The adjustable fulcrum blocks 12. 12 permitsuch an adjustment of thesefollow-up devices thatthe movement of the tothat of the low pressure valve without in any way influencing the ratioof lever transmission between the speed governor and the pilot valves.

The chamber below the abutment 18 is in communication with the source oflow pres sure steam and said abutment is connected with the lever 1 1which actuates the pilot valve 6. If, for any reason, the pressure ofthe low pressure steam falls, so that the amoun'tof such steam. is nolonger sufficient to maintain the normal speed of the turbine, then thespring 19 will force the abutment downward, and in so doing it will pulldown if .the load increases the manner shown and descri the twootherwise similar valveractuating motor and bring it back ing or thelever 14 and the pilot valve 6, which admits hydraulic pressure abovethe piston 3 and effects a downward movement of the stem 5'. Thisoperates through the 1on lever 22 to push up the pilot valve 6 and admitpressure below the piston 3, so that the ultimate effect is to admithigh pressure steam to the turbine to of low, pressure steam. Thischange from low to high pressure steam is effected posit-ively and quiteindependently of the speed of the engine so that at constant load,'novariation in the number of revolutions can occur by reason of a drop inthe supply of low pressure steam. Moreover, the partial closing of thelow pressure valve, which happens when. wardly, as explained above,operates to keep up the pressure of such low pressure steam as isavailable. It appears, therefore, that the simpleaddition of the lonmotors to perform the various functions and meet the various conditionsabove set forth. The modification shownin Fig. 2 is intended to meetcertain objectionable conditions which have been found to arise inoperation when the low pressuresteam is sup plied to the turbine from anaccumulator. The steam entering the accumulator at intervals and inlarge amounts from there'- ciprocat-ing engines or other sources, causesa sudden rise of pressure ahead of the'throttle valve, andsimultaneously also in the pressure-responsive device. The lattertherefore instantly moves into its extreme position and thus causes thelow pressure valve to be entirely opened. The engine thereupon speeds upuntil the speed governor closes the steam valve so far that ing throughit corresponds to the load on. the engine.

and corresponding irregularity in speed. .If the mixed pressure unit isconnected in parallel with other units, it'will, according the stem 5moves downlever 22 (1, enables.-

make up for the loss.

the quantity of steam flow- This varying steam pressure} thereforecauses a constant over-regulation'f to the newly-established speed,either fur- Y I nish work to the unit running in parallel with it, ortake Work therefrom, which of course is contrary to good operation. The

modification is desigged to obviate these difficulties. It will observedthat the transference of movement of the pressureresponsivedevice to thesystem of levers is effected indirectly through the operation of anauxiliary regulating device.

, The movable abutment or piston 24 working in the-cylinder 25 is urgedupwardly by the pressure of the steam in the accumulatorv conveyedtosaid cylinder through the pipe 26. A tension spring 27 acts againstthis pressure. The rod 28 attached to the piston operates the pilotvalve 29 in a sliding cassleeve 30, which contains ports 31prossure-responsive device from effecting the opening of the lowpressure and is connected to a lever 32 fulcrumed at Y 33 and carryingan eye 34 loosely encirclin the stem 5 of the high pressure valve 2. Atension spring 35 urges said sleeve to its lowest position whensaidlever is free to move. The pilot valve 29 controls the admission ofhydraulic pressure to the cylinder 36 in which is a piston 37 whose rod38 is pivotally attached to the leverlat at its fulcrum point. Fja'omthis construction it follows that a comparatively small pressuredifi'erence in the accumulator eauses when necessary a complete openingor complete closure of the low pressure valve 1, since there is nofollow-up device to return the pilot valve to a mid-position., Thesleeve 30 may be shifted by, the same amount as the length of the strokewhich the pressureresponsivc device is adapted to make when the pressurein the accumulator rises. The movement of the sleeve is dependent uponthe movement of the high pressure valve 2. If this is closed, as shownin the drawing, the stop 39 on the stem 5 acting through the lever 32lifts the sleeve to its extreme upper position. The stroke of the piston24 is so calculated that the pilot valve/29 closes the ports in thesleeve in this upper position, when the piston2-it has reached itsuppermost limit, In this conditioi i of'afi'airs the pressure-responsivedevice is incapable of valve 1 at the highest pressure in theaccumulator. Butwhen the accumulator pressure falls, the pilot valveopens the ports in the sleeve, so that the low pressure valve 1 willclose toisuch a point that the normal pressure is reestablished in theaccumulator. If, on the contrary, as for example in the case of thesimultaneous supmotor,

ply of low pressure and high pressure steam to the turbine, thehiglupressure valve 2 is also open to the desired amount, the spring 35pulls the sleeve into its lowest position, because the stop 39 hasreleased the lever 32. Since this condition assumes a lower, pressure ofaccumulator steam, the piston 24 will he at some intermediate point inthe sleeve cylinder, so that the pilot valve 29 can either rise or fallwith the varying no i cumulator pressure and either open or close 1 thelow pressure valve 1 as the case may require. With a rising pressure inthe accumulator the valve 1 is opened until, by the I operation of thelong lever 22 the high pres sure valve 2 becomes closed. This movement 1of the stem 5 operates through the lever 32 to lift the sleeve, and thusprevent the acting in case of ,further rise of accumulator pressure. Thelow pressure valve can now be opened wider, if necessary, only by theaction of the speed governor.

In accordance with the provisions of the patent statutes, I havedescribed the princontrolled long lever attached at ciple of operationof my invention, together with the apparatus which I now consider.

, apparatus shown is only illustrative, and

that the invention can be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is-

i. In a mixed pressure turbine, the combination with a high pressurevalve and a low pressure valve, of motors for operating said valves, apilot valve for each motor, a lever connected to each pilot valve, aspeed governor for operating said'levers simultaneously. and a longlever connected to the stem of the low pressure valve and pivotallyattached to and acting as the fulcrum' of the lever operating the pilotvalve of the high pressure valve motor.

2. In a mixed pressure turbine, the combination with a high pressurevalve and a low pressure valve. of motors for operating said valves, apilot valve for each motor, a

long lever attached at one end to the stem of the low pressure valve, apressure-responsive device, a speed governor, and levers pivotallyattached to said governor and to the pilot valves, one of said leversbeing ful- (ruined on the end of the long lever and the other on thepressure-responsive device.

3. I11 a mixed pressure turbine, the cu -tnbination with a high pressurevalve and a low pressure valve, of motors for operating said valves, aspeed governor, a system of lovers connecting both said motors to saidgov-'ernor, a motor connected to said system of lovers for attecting thelow pressure valve a pressure responsive device consaid last namedmotor, and means by the high pressure valve for rendering said lastnamed motor unrespon sive to any increase in pressure when the highpressure -alve is closed.

4. Ina mixed nessure turbine, the combination with a high pressure valveand a low pressure valve. of motors for operating said valves, a pilotvalve for each motor, a lever connected to each pilot valve, a speedgovcrnor for operating said levers simultaneously, a long leverconnected to the stem of the low pressure valve and pivot-allyattrolling tached to the lever operating the pilot valve of the highpressure valve. a pressure responsivc device connected to the governorlow pressure valve, of motors for operating said valves, a pilot valvefor each motor, a one end to the stem .said'pilot valve, and means ofthe low pressure valve, av pressure re- 'sponsive device, a speedgovernor,levers piv- 1 ctally attached to said governor and to the pilotvalves, one of said levers being ful- I crumed on the end of the longlever and l the other on the pressure responsive device, and means forrendering said pressure responsive device unresponsive to an increase inpressure when the high pressure valve is closed.

(i. In a mixed pressure turbine,'the combination with a high pressurevalve and a low pressure valve, of motors for operating said valves, aspeed governor. a pressure respoir sive device. a system of leversconnecting these two elements with the motors, a pilot valve controlledby the pressure-responsive device and admitting h vd"aulic pressure to acylinder containing a piston connected to the low pressure *alve motor,a slidable; sleeve containin n"ports cooperating with for shifting saidi high pressure valve.

T. In a mixed pressure turbine, the comg bmation w1th' a high pressurevalve and a low pressure valve, of motors for operating said valves, asystem of levers for controlling said motors, a motor connected to oneof said levers, a pilot valve for said last named motor, avpressure-responsive device for actuating said pilot valve, a sliding%sleeve containing ports cooperating with said pilot valve, and a leverconnected at one end to said sleeve and having its other end in the pathof a stop-on the high pressure valve. v

In witness whereof, I have hereunto set my hand this thirty-first day ofDecember, 1912.

v \VILHELM PAPE.

Witnesses:

HEXRY HAsPER, \VOLDEMAR HAUPT.

